There Appears to be Something Very Non-Universal about Apricon USB3 Devices on New Macs

Update – Because this page continues to get traffic from search engines, here’s a minor update for you: In the year since this was originally written, we haven’t seen these USB 3.0 problems with Macs aside from with these Apricon adaptors. The original posting could be taken to imply there was a problem with the USB 3.0 implementation on the newer Macs, but we suspect the issue is actually just with certain early USB 3.0 chipsets such as those used by this particular Apricon.

The original post:

As you probably know, USB3 is a relatively recent update to the USB standard, and it’s only supported at USB3 speeds on the newest Macs (2012 and newer Macs). The bad news is we’ve discovered something wonky about it, which we haven’t seen mentioned before. There appears to be an issue with certain chipsets and the way they “handshake” with OSX 10.8.3 and older, where OSX assumes that the drive attached is an MBR disk (Master Boot Record, an older MS format), and if the drive is actually in the newer GUID format (the current OSX standard), it will give you an error stating “This disk is unreadable, do you want to initialize?”. If you click yes, it will ask you to re partition the disk, which erases all data. If you say no, it simply will not mount the disk. We’re looking closer to see if we can find a work-around.

So far, we’ve seen this only with certain USB3 to sata adaptors from Apricon. More info as we find it.